Question

我有一个通过不同方式分配多个商品的对象。优惠仅适用于一个产品，而对象具有多个优惠。现在我想要一个对象的所有提供遵循一个特定的业务逻辑，只包含一次产品。

目前我已按如下方式实施：

List<Offer> offers = new List<Offer>();
List<Product> products = new List<Product>();                
this.AddOffersToList(offers, products, ov.Offers.Where(o => o.OfferType == composedOffer));
this.AddOffersToList(offers, products, ov.Offers.Where(o => o.OfferType == simpleOffer));
this.AddOffersToList(offers, products, ov.ComposedOfferList.Offers);
this.AddOffersToList(offers, products, ov.SimpleOfferList.Offers);

AddOffersToList方法：

private void AddOffersToList(List<Offer> offers, List<Product> products,IEnumerable<Offer> newOffers)
{
    foreach (Offer offer in newOffers)
    {
        // add offer only if the product is not contained yet
        if (!products.Contains(offer.Product))
        {
            offers.Add(offer);
            products.Add(offer.Product);
        } 
    }
}

这似乎不是最优雅和表现方式。 “约束”是AddOffersToList方法调用的顺序，并且Product仅包含一次。

非常欢迎任何有助于我更好地解决这个问题的事情！

Answer 1

此代码与我相信的相同。

var offers = ov.Offers.Where(o => o.OfferType == composedOffer)
    .Concat(ov.Offers.Where(o => o.OfferType == simpleOffer))
    .Concat(ov.ComposedOfferList.Offers)
    .Concat(ov.SimpleOfferList.Offers)
    .GroupBy(offer => offer.Product)
    .Select(group => group.First())
    .ToList();

var products = offers.Select(offer => offer.Product).ToList();

带有约束的Concat多个IEnumerables

1 个答案: